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An analysis of X(Twitter)'s new XChat features shows that X can probably decrypt users' messages, as it holds users' private keys on its servers
(blog.cryptographyengineering.com)
This is a most excellent place for technology news and articles.
seriously, that's the most convoluted wording possible for a simple statement. If they have the private keys they have the private keys and there's no need for analysis.
Weird, I didn't see 'probably' once in your reply.